JPH0329588A - Broad band magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the deterioration in the picture quality detected visually directly even when there is a characteristic difference between channels by dividing the same kind of signals into plural channels when a broad band video signal is subjected to channel split. CONSTITUTION:The device consists of filter means 17, 25 passing only a specific frequency component of a broad band video signal, frequency conversion means 19, 22 shifting the frequency component of a signal, and adder means 20, 21 adding the signal subjected to frequency conversion and other signals. Then the specific frequency component of the broad band video signal is used as one channel, and the signal subjected to frequency shift and other signals are added and the result is used as other channel thereby applying processing to the same kinds of signals to be divided into plural channel signals with equal bands for each scanning line. Thus, even when there is any characteristic difference between channels, the deterioration in the picture quality is avoided.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a wideband magnetic recording and reproducing device for recording and reproducing wideband video signals such as a high-definition video tape recorder. [Prior Art] FIG. 5 shows, for example, IEE Transac
tions on Consumer Electro
nics Vo sentence + GE-33, No. 3 of 203
208 is a block diagram showing the structure of the conventional wideband magnetic recording and reproducing apparatus using the channel division method shown on pages 1 to 208. FIG. In the figure, (1) is a matrix circuit (hereinafter referred to as MX circuit), which inputs three primary color signals of R, G, and H, and
The signal is converted into a luminance signal (hereinafter referred to as Y signal), a wideband color signal (hereinafter referred to as Cw signal), and a narrowband color signal (hereinafter referred to as Cn signal). (2) is the input selection circuit (hereinafter, IN
(referred to as the SEL circuit). (3A). (38) and (3G) are A/D converters that convert each of the Y signal, Cw signal, and Cm signal into digital signals. 0) is a vertical low-pass filter (hereinafter referred to as LSC) that performs line-sequential processing by alternately selecting the input Cw signal and Cn signal for each line. (5) is a time axis conversion multiple signal encoder (hereinafter referred to as TTM).
(hereinafter referred to as CH.
and C.H. A time-axis transformed multiplexed signal (referred to as B) is created. ([lA), (8B) are D/A converters, and CH. A and CH. Convert each H signal to an analog signal (7A). (7B) is a frequency modulator (hereinafter referred to as F
MMOI). (8A). (8B) is a recording amplifier (hereinafter referred to as REC AMP), which is connected to the above CH.
A and CH. Each analog signal of H is frequency modulated and amplified, and sent to the magnetic tape (27) via the magnetic head (2B).
Record it in . The recording system circuit is composed of each of the above components. (15) is a reproduction amplifier (hereinafter referred to as PBAMP).
(14) is an FM demodulator (hereinafter referred to as FM OEM) which amplifies the signal reproduced from the magnetic tape (27) via the magnetic head (28) and converts it into FM@774. (13A
), (13B) is an A/D converter. FM demodulated CH. A and CI. Convert the H signal to a digital signal. (12A). (12B) is the time vehicle correction device M (hereinafter referred to as .TB
(referred to as C) removes the time axis fluctuation component of the two-channel digital signal. (11) is a time axis conversion signal decoder (hereinafter referred to as TTM DEC) which decodes Y{3, Cw signal, and Cn signal. (10)
is a quadrature direction interpolation filter (hereinafter referred to as CIP). Interpolate each of the Cw signal and Cn signal. (9
^), +9B). (9G) is a D/A converter that converts the Y signal, Cw signal, and Cn signal into analog signals and outputs them as playback signals.

A reproduction system circuit is constructed by each of the following components. Next, the operation of the above configuration will be explained.

First, the operation of the recording circuit will be explained.

The input R. G. Each B signal is converted into a Y signal, %Cw signal, and Cn signal in the MX circuit (1), and then converted into an I signal.
N SEL circuit (2) and A/D converter (3^
), [3B). (3C) and is converted into a digital signal. The Cm signal and Cn signal thus converted into digital signals are input to L SC (4), where . C
Line-sequential processing is performed to alternately select and transmit the w signal and Cn signal every line, and when transmitting the line-sequentially processed Cm signal and Cn{δ signal every l line. After limiting the band of the generated vertical frequency components, the Cw signal and Cn signal are output alternately. In other words, when the output of the IN SEL circuit (2) is in the series shown in Figure 6, the output of the LSC (4) is the 7th one.
The series will be as shown in the figure. Then, the Y signal shown in Fig. 6 and the output of LSC (4) of the series shown in Fig. 7 are TTM ENC (5).
and in this TTM ENC(5), Y
The signal is time-expanded, and the Cw signal and Cn signal are compressed in time to the CI. A and CH. Create a two-channel time-base conversion multiplex signal of H. At this time, a synchronization signal (S) and a burst signal (B) are added to form a signal form as shown in FIG. Next, the output signal of TTM ENC (5) is D/A
Converter (GA). After being converted to an analog signal by (13B), FM M O D (7A),
(7B) R E C A M P (8A), (8
B), magnetic tape (27) via magnetic head (2 days)
is recorded in Next, we will explain the operation of the reproduction circuit. Magnetic tape (27) via magnetic head (28)
The signal reproduced from P R A M P (15A
)． (15B) and FM DEM (14A)
．． After being FM demodulated by (14B), it is converted into a digital signal by A/D converters (13A) and (13B) and input to TBS (12A) and (12B). This TBS (12A). After the time axis variable work year is removed in (12B). is input to the TTM DEC (11), and in this TTM DEC (11), Y
Separate the signal, Cw signal, and Cn signal and convert to the original time axis. Then, as shown in FIG. 7, the signals output from the TTM DEC (11) are the Cw signal . C
Since it is an n signal, line interpolation is performed in CIP (10). That is, in C I P (to), the Cw signal,
By interpolating each Cn signal, Cw and Cn signals are obtained for all lines. Next, the Y signal output of TTM D E C (11) and the output signal of cXp(to), that is, Cw
signal, Cn signal is D/A:! 7 barta (9A),
(98) and (9G)-t' are each converted into analog signals and output as playback signals. [Problems to be Solved by the Invention] Since the conventional broadband magnetic recording/reproducing device is configured as described above, the Y signal is divided into a plurality of channels for each scanning line and recorded and reproduced. If there are differences in characteristics between multiple channels, there is a problem in that, for example, differences in brightness occur from scan line to scan line, creating stripes of brightness and darkness, leading to deterioration of the reproduced image quality. This invention was made to solve the above-mentioned problems, and it is a broadband magnetic field that can suppress visually detectable image quality deterioration even if there are characteristic differences between multiple channels. The purpose is to provide a recording/playback device. [Means for Solving the Problems] A wideband magnetic recording and reproducing device according to the present invention includes a filter means that passes only a specific frequency component of a wideband video signal, and @
frequency converting means for frequency shifting the frequency components of the signal;
It is characterized by being provided with an addition means for adding the frequency-converted signal and another signal. [Operation] According to the present invention, a specific frequency component of a wideband video signal is set as one channel, and a frequency-shifted signal and another signal are added to form another channel. By dividing the same type of signal into multiple channels of equal bandwidth for each scanning line, image quality does not deteriorate even if there are differences in characteristics between channels. [Embodiment 1 of the Invention An embodiment of the present invention will be described below based on the drawings. FIG. 1 is a block diagram showing the structure of a broadband magnetic recording and reproducing apparatus according to an embodiment of the present invention.
(3A), (3B), (3G). (4). (13
A), (IB) to (8A), (8B). (9A).
(9B), (9G), (lO), (13A), (13
B) ~ (15A), (15B). (27), (28
) is the same as the conventional example shown in FIG. 5, so the corresponding parts are given the same reference numerals and detailed explanation thereof will be omitted.
In FIG. 1, (tS), (24). (2B) are delay elements (hereinafter referred to as DELAY'). (
17). (25) is a low pass filter (hereinafter referred to as LPF). (18). (23) is a subtractor, (19),
(22) is a frequency converter (hereinafter referred to as FS). (
2G). (21) is an adder. Next, we will explain the operation of the above configuration. Here, the input signals are a no vision video signal, a Y signal with a 20 MHz band, and two Cw and Cn signals each with a 5 MHz band.
Is the recording system and playback system 13MHz? It consists of two channels with an iF range. First, in the recording operation,
The three input signals, Y signal, Cw signal, and Cn signal, are A.
/D converter (3A). (3B). (3G)
Each is converted into digital data by Of these, the Cw signal and the Cn signal are processed line-sequentially in L SC (4). That is, as shown in FIG.
The sword is issued from C (4). On the other hand, the Y signal is passed through an LPF (l7) with the characteristics shown in Figure 2.
After being processed by. The signal is input to the D/A converter (6A) and converted back to an analog signal. This Y signal has a delay amount equal to L P F (17) above.
It is also added to L A Y (1B), and by subtracting the output of L P F (1?) from its output in the subtracter (18), the Y signal as shown in Figure 3 (a) is obtained. The high frequency component (vh) is extracted. Subtractor (1
The Y signal high frequency component (vh) which is the output of 8) is F S
(19), as shown in Figure 3(b), 7 MH
After being shifted to the lower frequency side by z, the signal is added to the Cer signal and the Cn signal in an adder (20). Therefore, the spectrum of the output signal of the adder (20) is shown in Figure 4 (
b). Then, the output of the adder (20) is sent to the D/A converter (
6B) into an analog signal. As a result, the D/A converter (8) outputs the Y signal low frequency component (Y sentence) as shown in FIG. 4(a), the Cw or Cn signal as shown in FIG. 4(b), and the Y@ signal as shown in FIG. No. high frequency component (Yh)
Since two mixed signals with equal bands are obtained, these are frequency modulated as channel 1 (CH.l) and channel 2 (CH.2) and recorded on the magnetic tape (27). Next, in the playback operation, F
After M demodulation, A/D converter (13A), (1
3B) as digital data and channel 2 (
C.I. From the signal of 2), Cw is obtained by L P F (25)
Extract the signal and CXI signal. In addition, the signal of channel 2 (C}1.2) is
D E L A Y (2
4), the output of L P F (25) is subtracted in a subtracter (23). Therefore, the subtractor (
The output of 23) is the frequency-shifted Y signal high frequency component (
Yh) is obtained, so 7 MH with F S (22)
By shifting z toward the high frequency side, the original Y@ high frequency component (Yh) as shown in Fig. 3(a) can be obtained. i of the Y signal high frequency component generated by such a series of processing
l! ! The delay time is calculated by DELAY C2B) and the Y@ low frequency component (YJI) of channel 1 (CH.1).
), and then in the adder (21), F S
By adding the output of (22) and the output of DELAY (213), the original Y signal is obtained. On the other hand, since the Cm signal and Cn signal which are the outputs of L P F (25) are interpolated by C I P (10),
The output of this C I P (10) contains Cw and C! for all lines. I can obtain each signal. Next, the digital data of the Y signal output from the adder (21) and the C output from CIP (10) are
W signal and Cn signal are each D/A converter (9A)
, (9B) and (8G) are converted into analog signals and reproduced and output. In addition, in the above example. A/D converter (3A
), (3B), (3C). (13A) and (13B), after digitization, predetermined processing is performed, but the same effect as in the above embodiment can be obtained even when similar processing is performed on analog signals as they are. [Effects of the Invention] As described above, according to the present invention, when dividing a broadband video signal into channels, processing is performed to divide the same type of signal into a plurality of channels for each scanning line. Even if there are characteristic differences between channels, direct
This prevents visually detectable deterioration of image quality.

[Brief explanation of drawings]

FIG. 1 shows a broadband magnetic recording/reproducing Ml! according to an embodiment of the present invention. Block diagrams showing the structure of the
The figures are a frequency characteristic diagram and a signal spectrum for explaining the operation of Fig. 1, Fig. 5 is a block diagram showing the configuration of a conventional wideband magnetic recording and reproducing device, Figs. 6, 7, and 8.
The figure is a signal sequence diagram for explaining the operation of the conventional example shown in Figure 5. (+7). (25)...Low pass filter (LPF)
, (18). (23)...Subtractor, (19), (22
) - Frequency converter (FS). (20). (
21) --Adder. Note that the same symbols in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) Filter means for passing only a specific frequency component of a wideband video signal, subtraction means for subtracting the output signal of this filter means from the input signal of this filter means, and frequency component of the output signal from this subtraction means 1. A wideband magnetic recording and reproducing device comprising: a frequency converting means for shifting; and an adding means for adding an output signal of the frequency converting means and another signal.